Pneumatically operated nail driver

ABSTRACT

The disclosure concerns an attachment to a power tool, such as a pneumatic driver, which will retain and drive a nail into hard material such as concrete or steel. The device comprises telescopically mounted sleeve members, in which an axially reciprocable striker is received, a spring urging the member apart, and stop shoulders to limit member expansion so that collapse of the members is required to effect delivery of hammer impacts via the striker to the nail head received by one of the members.

i United States Patent 721 111mm Morris Doberne 555$ Morelh Ave., North Hollywood,

2,543,942 3/1951' Shaff 3,060,441 10/1962 Henning Calif. 91607; Robe s. H I 730 Chaucer Road 88 Primary Exam ner-Granville Y. Custer, .lr. M can guos 1 AnomeyWh1te and Haefliger rim, 7 [2|] AppLNo. 861,599 [22] Filed Sept. 29,1969 [45] Patented Aug.3l, 1971 54 PNEUMATICALLY OPERATED NAIL DRIVER I l l Chin, 5 Dnwhg Figs I ABSTRACT: The disclosure concerns an attachment to a power tool, such as a pneumatic driver, which will retain and [52] [1.8. CI 227/147 drive a nail hard material such as concrete or steel. The [51] u B25: 7/00 device comprises telescopically mounted sleeve members, in 0' m... u an axially r-eciprocable striker is received a Spring urg.

ing the member apart, and stop shoulders to limit member ex- [56] Ream Cm pansion so that collapse of the members is required to eifect UNITED STATES PATENTS v delivery of hammer impacts via the striker to the nail head 1,699,519 1/1929 Brown 227/147 received by one of the members.

1 53/ efad a5 a2 PNEUMATICALLY OPERATED NAIL DRIVER BACKGROUND OF THE INVENTION This invention relates generally to nail driving and more particularly concerns attachments to power tools capable of driving nails (as for example concrete nails) in an unusually simple and effective manner.

There is a need at the present time for a simple and reliable attachment to a power tool, such as a pneumatic driver, which will retain and drive a nail into concrete, steel or other hard materials in response to pressure exerted by the attachment of the nail. Prior nail-driving devices of which we are aware lack the required simplicity and capability for attachment to existing pneumatic drivers.

SUMMARY OF THE INVENTION Accordingly, it is a major object of the invention to fill the above need through the provision of an unusually simple and reliable attachment which will function as described when connected with a tool that includes an axially reciprocable hammer and a part in which the hammer projects. Basically, the device comprises first and second coaxially and telescopically mounted sleeve members, the first having a tubular terminal sized to receive a nailhead and a nail flange spaced from the head so as to directionally orient the nail relative to such members, the second member having a connection to removably interfit the tool part; an axially elongated and reciprocable striker extending coaxially within the members, one end of the striker located to face the nail head received by the terminal, and the opposite end of the striker located to receive repeated impacts delivered by the hammer; and a spring urging the members in an expansion direction, and stop shoulders on the members to limit relative expansion thereof at a position characterized in that relative collapse of the members is then required to effect delivery of hammer impacts via the striker to the nailhead.

As will be seen, additional interengageable shoulders are typically included on the striker and on the second member to limit displacement of the striker toward the tubular terminal so that the one end of the striker is kept out of nail dislodging position when the members are initially fully extended. The nail shank is at such times receivable to considerable extent within the tubular terminal. Also, a spring may be located between the striker and the attached tool part to urge the striker in an axial direction away from the hammer, for purposes as will appear.

Additional objects include the provision of a tubular terminal mouth sized to receive the nail guide flange with frictional interfit and a series of flats being of unusual advantage for this purpose; and the provision for guiding of the striker within the tubular terminal.

These and other objects and advantages of the invention, as

well as the details of an illustrative embodiment, will be more I fully understood from the following drawings, in which:

DRAWING DESCRIPTION DESCRIPTION OF PREFERRED EMBODIMENT In the drawings, the nail driving apparatus 10 is shown as connected with a pneumatic tool 11 that includes an axially reciprocable hammer l2 and a part 13 in which the hammer projects. A duct 9 delivers motive air to tool 11.

Part 13 is axially recessed at 14 for purposes as will appear; also, it is externally threaded at 15 for removable connection with the apparatus 10, the latter having a bore 16 threaded at 17 for attachment reception of thread 15.

The apparatus 10 includes first and second coaxially telescopically mounted sleeve members 18 and 29 respectively, member 18 having a reduced tubular terminal 18a. The latter is sized, as by means of a bore 20 and counterbore 21 to receive a nail head 22 and nail flange 23 spaced from head 22, thereby to directionally orient the nail coaxially relative to members 18 and 19. Note also the step shoulder 24 formed between the bore and counterbore, to seat the annular flange 23. The nail shank 25 penetrates the flange 23 to be guided by the flange during advancement into the work, as for example the channel 60 (not predrilled) to be connected to concrete layer 26.

An axially elongated and reciprocable striker 27 extends coaxially within members 18 and 19, one end 27a of the striker located to face the nailhead 22. The enlarged opposite end 27b of the striker is received in bore 14 to receive repeated impacts delivered by the hammer. In this regard, the striker is guided for endwise reciprocation, and with unusual advantage and simplicity, by means of the bores 20 and 14, an annular flange 28 retained on the striker having a loose guide fit in bore 14. Spring 29 fits between that flange and the inner face 30 in part 13, to urge the striker in a direction away from the hammer 12.

Another and larger coil spring 31 is received within members I8 and 19 so as to urge them in an expansion direction, i.e. toward FIG. 2 condition. In the latter condition, stop shoulders 32 and 33 on the member flanges 34 and 35 respectively are interengaged to limit such expansion at a position characterized in that relative collapse of the members is then required to effect delivery of hammer impacts via the striker to the nailhead. Thus, in FIG. 2, the length of the striker is less than the distance between the nailhead 22 and end of the hammer 12. A second pair of stop shoulders 36 and 37 respectively on the flange 28 and on a nonmetallic shock absorber washer 40 limit travel of the striker toward terminal 18a so that a nail shank may be initially received in bore 20 when members 18 and 19 are fully expanded, as in FIG. 2. Note that the washer 40 seats on flange 41 of reentrant cup-shaped extension 19a of member 19.

During driving of a nail shank 25 into work 26, the member 19 is collapsed relatively downwardly onto member 18 as by manually exerted downward pressure on tool 11, to allow impacting of the striker by the air-actuated hammer l2, flange 28 being lifted from washer 40 which fits loosely on shank 27b. As driving proceeds, the nail head 22 is advanced downwardly in bore 20, as seen in FIG. 3, and the lower end of tubular terminal 18a comes to rest on the surface of the work 26. FIG. 4 shows the nail completely driven into the work.

Note that outwardly turned flange 34 on member 18 guides on bore 45 of member 19, and that inwardly turned flange 46 on member 19 guides on cylindrical surface 47 on member 18.

It is a further feature of the invention that the mouth of tubular terminal 18a may be sized to receive the flange 23 with sufficient interference as to frictionally retain the flange during initial reception of the nail by that terminal (i.e. in FIG. 2). For that purpose, the terminal counterbore 21 may define several flats 48 for tangent interfering contact with the periphery of the flange, thereby to frictionally retain the flange. The nail shank may also have light frictional interfit with the flange, so as to be retained in FIG. 2 position prior to downward application of the nail tip to work 26.

Finally, it should be understood that terminal 18a may be recessed or counterbored to accept other types of main guides or flanges. In this regard, the flange 23 may be metallic or nonmetallic, and may even be frangible so as to break apart when the nailhead is driven against it allowing the head 22 to engage the work 60.

We claim:

1. Nail-driving apparatus connectable with a tool including an axially reciprocable hammer and a part in which the hammer projects, comprising a. First and second coaxially mounted members, the first having an integral relatively thick-walled tubular terminal defining a bore sized to receive a nailhead and a counterbore sized to receive a nail flange spaced from said head thereby to directionally orient the nail relative to said members, and the second member having a connection thereon to interflt said part,

b. an axially elongated and reciprocable striker extending coaxially within said members, one end of said striker located to face said nail head received by the terminal and the opposite end of the striker located to receive repeated impacts delivered by said hammer, and

c. a spring urging said members in an expansion direction,

and stop shoulders on said members to limit relative expansion thereof at a position characterized in that relative collapse of the members is then required to effect delivery of hammer impacts via said striker to the nail head,

d. said bore directly receiving said striker and said counterbore receiving the flange with sufiicient interference as to frictionally retain the flange against dropout during initial reception of the nail and flange by said terminal, said nailhead closely slidably received in and engaging said bore and said nail flange frictionally received in said counterbore, the nail extending vertically with frictional interfit to the flange, and structure limiting downward displacement of said striker and characterized in that the striker is kept from engaging and downwardly dislodging the nail head from the bore at times when said members are fully expanded, said structure including a flange shoulder on the striker engageable with another flange shoulder on a tubular section projecting axially toward said tubular terminal and within a cylinder defined by said second member. 

1. Nail-driving apparatus connectable with a tool including an axially reciprocable hammer and a part in which the hammer projects, comprising a. First and second coaxially mounted members, the first having an integral relatively thick-walled tubular terminal defining a bore sized to receive a nailhead and a counterbore sized to receive a nail flange spaced from said head thereby to directionally orient the nail relative to said members, and the second member having a connection thereon to interfit said part, b. an axially elongated and reciprocable striker extending coaxially within said members, one end of said striker located to face said nail head received by the terminal and the opposite end of the striker located to receive repeated impacts delivered by said hammer, and c. a spring urging said members in an expansion direction, and stop shoulders on said members to limit relative expansion thereof at a position characterized in that relative collapse of the members is then required to effect delivery of hammer impacts via said striker to the nail head, d. said bore directly receiving said striker and said counterbore receiving the flange with sufficient interference as to frictionally retain the flange against dropout during initial reception of the nail and flange by said terminal, said nailhead closely slidably received in and engaging said bore and said nail flange frictionally received in said counterbore, the nail extending vertically with frictional interfit to the flange, and structure limiting downward displacement of said striker and characterized in that the striker is kept from engaging and downwardly dislodging the nail head from the bore at times when said members are fully expanded, said structure including a flange shoulder on the striker engageable with another flange shoulder on a tubular section projecting axially toward said tubular terminal and within a cylinder defined by said second member. 